|
|
| Europium | |
| Electron Configuration | 2,8,18,25,8,2 |
| Electron Configuration | [Xe] 4f7 6s2 |
| Ground state | 8S°7/2 |
| Atomic Volume | 28.9 g/cm3 |
| Electronegativity | 1.2 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 2.76 x 10-7 |
| Molar magnetic susceptibility | 4.1942 x 10-8 |
 Thermal Properties |
|
| Enthalpy of Atomization | 180 kJ mol-1 @25°C |
| Enthalpy of Fusion | 10.5 kJ mol-1 |
| Enthalpy of Vaporisation | 176 kJ mol-1 |
| Heat Capacity | 27.66 J mol-1 K-1 |
| Thermal Conductivity | 13.9 W m-1 K-1 |
| Thermal Expansion | 35 μm m-1 K-1 |
| Hardness |
|
| Vickers hardness | 167 MPa |
| Elastic Properties |
|
| Bulk modulus | 8.3 GPa |
| Poisson ratio | 0.152 |
| Shear modulus | 7.9 GPa |
| Young's modulus | 18.2 GPa |
| Electrical Properties |
|
| Electrical resistivity | 9.0 x 10-7 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 1.8899 g Ah-1 |
| Electron Work Function | 2.5 eV |
| Valence Electron Potential (-eV) | 45.6 |
| Ionization Potential | |
 First
|
5.67 |
| Second
|
11.245 |
| Third
|
24.926 |
| Energy Levels |
|
| Kα1 (intensity 100) |
41.5422 KeV |
| Kα2 (intensity 50) |
40.9019 KeV |
| Kβ1 (intensity 22.7) |
47.0379 KeV |
| Kβ2 (intensity 7.9) |
48.2018 KeV |
| Kβ3 (intensity 9.3) |
46.8984 KeV |
| Lα1 (intensity 100) |
5.8457 KeV |
| Lα2 (intensity 10) |
5.8166 KeV |
| Lβ1 (intensity 45) |
6.4564 KeV |
| Lβ2 (intensity 17) |
6.8432 KeV |
| Lβ3 (intensity 10) |
6.57 KeV |
| Lβ4 (intensity 4) |
6.4364 KeV |
| Lγ1 (intensity 6) |
7.4803 KeV |
| Lγ2 (intensity 2) |
7.7645 KeV |
| Lγ3 (intensity 2) |
5.815 KeV |
| Ll (intensity 4.5) |
5.1763 KeV |
| Atomic Radii |
|
| Empirical
|
185 pm |
| Bohr Radius
|
231 pm |
| Covalent Radius
|
185 pm |
| Van der Waals
|
No data. |
| Triple covalent
|
No data. |
| Metallic
|
208.4 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 2 | VI | 1.31 | 1.17 | |
| VII | 1.34 | 1.2 | ||
| VIII | 1.39 | 1.25 | ||
| IX | 1.44 | 1.3 | ||
| X | 1.49 | 1.35 | ||
| 3 | VI | 1.087 | 0.947 | R |
| VII | 1.15 | 1.01 | ||
| VIII | 1.206 | 1.066 | R | |
| IX | 1.26 | 1.12 | R | |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
| Oxidation States |
|
| Main
|
Eu+3 |
| Other
|
Eu+2 |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
546.7 |
| M+ - M2+ |
1085 |
| M2+ - M3+ |
2404 |
| M3+ - M4+ |
4110 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 863 | 957 | 1072 | 1234 | 1452 | 1796 |
| Crystal Structure |
|
| Structure
|
Body centred cubic |
 |
a = 458.1 pm |
| b = 458.1 pm | |
| c = 458.1 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |